common: Drop log.h from common header

Move this header out of the common header.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/drivers/usb/eth/smsc95xx.c b/drivers/usb/eth/smsc95xx.c
index ab6411f..82fea74 100644
--- a/drivers/usb/eth/smsc95xx.c
+++ b/drivers/usb/eth/smsc95xx.c
@@ -9,6 +9,7 @@
 #include <common.h>
 #include <dm.h>
 #include <errno.h>
+#include <log.h>
 #include <malloc.h>
 #include <memalign.h>
 #include <net.h>